Consolidated Statements of Income and Comprehensive Income (unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Interest income
Interest and fees on loans	$ 177,566	$ 171,157
Interest on taxable securities	4,239	6,118
Interest on nontaxable securities	186	141
Interest on deposits in other banks and federal funds sold	1,383	534
Total interest income	183,374	177,950
Interest expense
Interest on deposits	4,092	6,798
Interest on other borrowings	6,738	6,175
Total interest expense	10,830	12,973
Net interest income	172,544	164,977
Provision for loan losses	(2,734)	(16,579)
Provision for unfunded commitments	9,009	(11,839)
Provision for other credit losses	(44)	(173)
Provision for credit losses	6,231	(28,591)
Net interest income after provision for credit losses	166,313	193,568
Noninterest income
Service charges on deposit accounts	11,058	10,829
Mortgage banking activity	62,938	98,486
Other service charges, commissions and fees	939	1,016
Net loss on securities	(27)	(12)
Other noninterest income	12,003	7,654
Total noninterest income	86,911	117,973
Noninterest expense
Salaries and employee benefits	84,281	95,985
Occupancy and equipment	12,727	11,781
Data processing and communications expenses	12,572	11,884
Credit resolution-related expenses	(965)	547
Advertising and marketing	1,988	1,431
Amortization of intangible assets	5,181	4,126
Merger and conversion charges	977	0
Loan servicing expense	8,919	5,900
Other noninterest expenses	18,140	17,144
Total noninterest expense	143,820	148,798
Income (loss) before income tax expense	109,404	162,743
Income tax expense	27,706	37,781
Net income	81,698	124,962
Other comprehensive income (loss)
Net unrealized holding losses arising during period on investment securities available-for-sale, net of tax benefit of $(4,633) and $(1,972)	(17,431)	(7,415)
Total other comprehensive income (loss)	(17,431)	(7,415)
Comprehensive income	$ 64,267	$ 117,547
Basic earnings per common share (in dollars per share)	$ 1.18	$ 1.80
Diluted earnings per common share (in dollars per share)	$ 1.17	$ 1.79
Weighted average common shares outstanding
Basic (in shares)	69,346	69,392
Diluted (in shares)	69,661	69,741